Piston



Jan. 3; 1928. 1,655,177

J. A. BROCKMEYER PISTON Filed Auz. 17. 1926 3 Sheets-Sheet l INVENTOR:

jsE'Pfl/y EFOGAMEYER,

J. A. BROCKMEYER Tan. 3, 1928.

PISTON 3 Sheets-Sheet 2 .Filed Auz. 17. 1926 @sewuffimamwrflt,

I BY

L V ATTORllER.

.- 1 My invention relates to a new and useful the several segments of the wall of the piston a ternate intermediate Patented-lamb. 192 8.

UNITED srArE'sl PATENT OFFICE.

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. OI PHILADELZHIA,

PENNSYLVANIA.

mom Application fled. August 17, me. sem Io. 12am.

piston for internal combustion engines, and relates more particularl to the ring less and self-expansive type 0 piston having 1ts outer walls made in sections adapted to expand outwardly ainst the inner surfaces of the cylinder, wit constant and umform pressure.

My invention relates more particularl to a-self-expansive pistonof this type, in w ch are joined along inclined lines and whereby moreover a tight joint is obtained between. the various segments and maintained by the same pressure which urges the segments of the iston outwardly agamst the cylinder.

ith the above ends in view my invention consists of an inner core or body "and outer cylindrical shell surrounding the same and interlocking therewith against a longitudlnal displacement with respect to each other, by means of suitable annular grooves, and annular tongues seated therein, said outer shell being formed of a series of segments, alternate ones of which are spring pressed from within, and are adapted to urge outwardly the ad acent and contiguous segments.

My Invention further consists of an outer segmented shell, comprising alternate spaced s ring pressed wedge segments, joined with segments, along oppositely inclined surfaces, of suitable angles, whereby the spring pressed wedge segments will act as we ges betweentwo adjacent intermediate segments, thereby to force the two adjacent segments upwardly and away from each other.

I and reliable results, althou For the .tion I have shown in the accom anying drawings several forms thereof which are at res- I out preferred by me, since the same ave n found in practice to i've satisfactory g it is to be understood that the various instrumentalities of which m arranged and organized and that my invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

Referring to the drawings Figure 1, represents a'front elevation of a piston embodying my invention.

purpose of illustrating my invenbod invention consists can be variously.

FIiJgure 5, represents a section on line 5-5 of 1 gure 6. Figure 6, represents a section on line 6-6 of Iugure 5.

-Figure 7, represents a rear elevation of one of the intermediate segments of the outer shell of the piston.

represents a bottom plan view Figure 8, represents a rear elevation of one of the spring-pressed wedging segments of the outer shell of the piston.

Figure 9, represents a front elevation of a modified form of piston embod ing my invention, and similar to that s own in Figure 1.

Figure 10, represents a horizontal section on line 1-010 of Figure 11, of another modified form of piston embodying my invention.

Figure 11, represents a front elevation of the same.

Referring to the drawings, in which like reference characters indicate like parts.

1 designates the inner core or body of the piston, having the upper wall 2, the substantially. c lindrica'l and vertical pendant wall 3, which may be cut away as at 4, for the ur ose of reducing the weight thereof, and aving the two aligned, inwardly projecting horizontal bosses '5 and 6, for receivin a wrist pin, (not shown in the drawings). e upper wall 2 of the body or core 1, overhangs the vertical cylindrical wall 3, ofsaid y or core, in a laterally projecting annular flange 7.

- A lower terminal annular flange 8, is also carriedby the vertical cylindrical wall 3 of the body 1, in substantial vertical alignment with the upper flange 7. These flanges serve to interlock with corresponding inwardly projecting flanges of the outer segmented shell of the. piston, to prevent axial dis placement of one with respect to the other. 9 and 10 are additionalxlaterall projecting spaced annular flanges, spaced om the upper flange 7, and also spaced from each other a suitable distance. The outer segmented cylindrical shell 11 of the piston is formed of alternate spring pressed wedge segments 12 and intermediate segments 13 respectively. In the illustration shown in Figures 1 to 9 inclusive there are three of each, six in all.

In order to prevent any leakage past the piston in anaxial direction, the joints be portion plane, that is,

tween the adjacent segments are formed along an incline. tration shown in Figures 1 to 8 inclusive, the intermediate segments 13 are formed with opposite inclined and diverging edges 14 and 15. The edges 14 and 15 are con tinued inwardly in plain surfaces 16 and 17, which, in the modification shown in Figures 1 to 8 inclusive, are formed in the same as shown in Figures 6, are in alignment with each other. The joint surfaces 16 and 17 are formed along suitable inwardly extending ribs 18 (Fig. 6) which are formed integral with the cylindrical wall portion 19 of the segments. This construction is preferred as it imparts an added lightness to the piston.

The spring pressed or wedge segments 12 are provided with correspondlng converging edges 20 and 21 formed at the sameangle as the edges 14 and 15, and continue 1n corresponding inclined joint surfaces 22, also formed on corresponding flanges or ribs 23, which are formed integrally with the relatively thin cylinder wall 24 of said segments 12. The angle of inclination between the two joint surfaces 22 of the segments 12, in the illustration shown in the drawings is substantially an angle of degrees, since that angle has been found in practice to be most effective. Other suitable angles may be employed however.

Each of the spring pressed or wedge segments 12 is provided with flat rear spring seats 26 (Figure 8), adapted to receive the terminals 27, of a flat bowed spring 28, the central bowed portion of which is seated in a. suitable recess 29, in the cylindrical wall 3 of the inner core\or body of the piston. By this means the spring pressed or wedge sections 12, are pressed outwardly in a radial direction, uniformly at both ends, and in a yieldable manner. This spring pressure is thus brou ht to bear between the c lindrical outer surfaces of the wed e sectlons 12 and the inner wall of the cy inder.

Due however to the converging joint surfaces 22 of the wedge segments 12, however, and the corresponding inclined surfaces 16 and 17 of the intermediate sections 13, said intermediate sections 13 are also urged outwardly and away from each other in a substantially radial direction, by the same spring pressure.

By this 'novel construction it will therefore be seen that not only are the cylindrical surfaces of the segments 12 and 13 pressed outwardly against the inner surface Accordingly in the illus-' of the cylinder uniformly and constantly, but any wear on the cylindrical surfaces of the segments, or on the cylinder wall is automatically compensated for by the expansion of the segments, without however in any way loosening the joint between the inclinedsurfaces 22 and 16 and 17 of said wedge sections 12 and intermediate sections 13 respectively.

Due to the inclination of the joint moreover, between the segments, any slight leakage at the joint is practically eliminated, be-

cause the force of both the compression and suction is in an axial direction and not parallel to the joint.

In order to prevent any leakage being be-. hindthe outer segmented shell 11, of the piston and the inner core or body 1 of the same,

a plurality of laterally and inwardly pro- I illustrated a plston construction embodying my invention, in which the outer segmented expansion shell of the piston, is divided into While in Figures 1 to 8 inclusive Ihave alternate diamond shaped wedging segments and intermediate segments, yet, it is within the scope of my invention to form the outer shell 11 of substantially triangular segments 34 and 35 (Figures 9) having their apices projectin alternately upwardly and downwardly, thereb also providing the inclination joint 36; t 1e interior construction being substantially the same as that of thev construction shown in Figures 1 to 8 inclusive.

In Figures 10 and 11 I have illustrated a further modification of my novel piston construction. wherein each segment also produces a wedglng action on the adjacent segment, and whereby the number of se ents is thus reduced to one half. 1 Thus, in this modification, the segments 37, 38 and 39 are all formed alike, of a generally rhomboidal shape; the upright incoined edges 40 and 41 of each segment being formed in similarly inclined surfaces as shown in Figures 10 and 11. Thus the contiguous and coacting joint surfaces 42 and 43 of each two adjacent segments cooperate with each other; the former effecting a wedging action on the latter, to expand outwardly the segmented shell springs 44, similar to the springs 28 of the modification heretofore described and shown in Figure 5, are interposed between the core or body 1, and the wedging side of each of the segments 37, 38 and 39, and positioned at an angle, substantially parallel to the joints of the segments, as indicated in dotted unefin Figure 11. By this means,"

' thereof, which will one sideof each segment 37, 88 and 39 is urged outwardly in a radial direction by the direct action of a spring 44, while the other side ofthe same segmentis :urged outwardly by the wedging action between the inclined ioint surlgaces 42 and 43, as will be seen from 1 re w t will now be apparent that I have devised a new and use 1, construction in pis tons, which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description, and while I have in the present instance shown and described preferred embodiments give in practice satisfactory and reliable results, it 1s to be understood that such embodime out departing from the spirit or scope of emventionor sac ificing any of its advantages.

a Having thus' described' my invention what plurality of substantially I mond shape,

clalm as new and desire to secure by Letters Patent, is:

1. A piston comprising an inner core memoutwardly.

2. A pistoncomprising an inner core member, an outer segmented cylindrical shell surrounding said core member being formed of a plurahty of substantially diamond-shaped V the latter outwardl nts are susceptible of modification in various particulars withsegments havi outwardly convergeach two wedge segments, having sponding joint surfaces contiguous with the joint surfaces of'said wedge segments, and means operatively interposed between each of said wedge segments and said core urging 3. A. piston comp ising an inner core memher, an outer segmented cylindrical shell surrounding said core member, formed of a plurality of substantially diamond-shaped wedge segments having outwardly .converging "ointsurfams formed along Said diamon shape, intermediate segments between each two -wed sponding joint joint surfaces of said wedge segments, resilient means urging said wedge segments outwardly, and means interlocking said inner core with the outer shell against any relative axial movement between the two.

4. A piston comprising an inner core member, an outer segmented cylindrical shell surrounding said core member, formed of a plurality of substantially diamond-shaped wedge segments, having outwardly converging joint surfaces formed along said diamond shape, intermediate segments between each two wedge segments, having corresponding joint surfaces contiguous with the joint surfaces of said wedge segments, means operatively interposed between each of said wedge segments and said core ur ng the latter outwardly, and alternate locilng annular flanges carried by saidinner core and said outer shell respectively to form a gas tight joint between the two.

JOSEPH A. BROCKMEYE'R.

mg oint surfaces formed along said die- 'mon shape, intermediate segments between correge segments, having corresurfaces contiguous with the 

